Push-button control



Nov. 7, 1939. A. w. FRANKLIN 2,l78,958

PUSH-BUTTON CONTROL Filed Nov. 16, 1937 llll! lllll Patented Nov. 7, 1939 UNITED STATES PATENT ori-ICE Albert W. Franklin, New York, N. Y.

Application November 16, 1937, Serial No. 174,810

10 Claims.

The present invention relates to means for the control of the tuning element of a radio apparatus, and speciiically to newy and useful improvements in selective tuning thru the medium oi 5 depressible buttons.

It is an object of this invention to provide mechanical means for setting the tuning element of a radio apparatus .into predetermined positions.

l One of the features of this invention resides in the accuracy with which predetermined stations may be tuned in. Other features reside in the simplicity of construction of the preferred form of my invention wherein the number of essential parts required are reduced to a minimum, and. the entire mechanism, with the exception of screws and thc like, can be die-cast and assembled at a very low cost.

Other objects and features will become apparent from the following specification and the accompanying drawing in which^ like reference numerals indicate identical parts' inthe various Views, and in which:

Fig. l is a front view of the preferred form of the mechanism with the front plate partially removed; I

Fig. 2 is a section taken along line 2-2 of Fig. l showing the depressible button and its co-operating cam;

Fig. 3 is a section of Fig. 1, taken along line 3 3, showing the link between the mechanism herein described and the tuning element of the radio apparatus;

Fig. 4 is a top view of Fig. 5, taken along line 4 6;

Fig. 5 shows a variation of the cam portion of my device as shown in Figures 1 and 2; and

Fig. 6 indicates the light mounting means employed to light up the station indicating means.

40 The mechanism consists essentially of 'three parts: the depressible button or cam operating means, the adjustable cam means, and the operable link between the cam and the variable condenser or tuning element of the radio apparatus.

The front view of the button and its housing is shown in Fig. 1, a side view is shown in Fig. 2,

semi-circular indentation 6 to fit around the cotter-pin 'I (to be more fully described later).

A plurality of buttons 2 are carried by plate 8. The plate 8 contains equally spaced slots 9 into which blades I are inserted. Slots 9 extend some 5 distance back from plate 8 in bosses III and serve as guides to support the blades. The slots 9 contain longitudinal semi-circular grooves I I to coincide with slot when the blades I are in place. Close to the free end of boss IIJ, along the center- 10 line thereof, is hole I2 to accommodate cotter pin "I,

The buttons and the plate 8 are assembled in the following manner: A helical' spring'V I3 is placed in a cup Id, (cup Iii has a hole (not shown) 15 centrally located therein to accommodate pin 5 of blade I) the cup and spring are placed within slot d of blade I, and the combination is inserted into slot 9 of the plate. When the blade is partially inserted into slot Q, cotter pin 'I is inserted 2o thru hole I2 and the blade is manipulated so that when it finally protrudes thru boss I0 the Cotter-pin is entirely thru hole I2 and can be bent back, and spring I3 is slightly compressed between the pin 'land the pin 5. Thus the buttons 25 2 are made yieldable from what shall hereafter be referred to as the inoperative position in plate 8 by springs I3.

Opposite each wedge 3 of blade I, on a rotatable shaft I5, are adjustable wing cams I 6. These 30 cams are spaced from each other by their own hubs I'I, and screws I8 therein fix them to shaft I5. The angle between the wings I9 and 20 of the cams is equal to the angle of the wedge 3. The total rotative displacement of shaft I5 is 35 such that at all times the cam is in operable position with respect to Wedge 3 which acts in reverse to a cam follower, and when button 2 is depressed the wedge and cam are made to coincide. When wedge 3 and cam I6 coincide set 40 screw I8 is opposite the hollow tube 2I cast integral with plate 8.

'I'he rotative displacement of cams I 6 are transferred thru shaft I5 to gear 22 xed thereon. Gear 22 in turn transmits its motion to gear 23 which is xed to shaft 2li by set screw 25. Shaft 24 is an extension from the variable condenser (not shown) Also fixed to shaft 24, by set screw 26, is the drum type of indicator dial 2l between knurled end discsv 28. 50

In Fig. 3 gears 22 and 23 are represented by their respective pitch circles. There is also the A-frame 29 by which shaft I5 is supported in position with respect to front plate 8. Plate 8 can be mounted by usual means thru holes such as 30 55 to the front panel 3| of the radio apparatus. Panel 3| must contain apertures corresponding to the apertures in plate 8; thru these apertures set screws I8 must be accessible, and blades I and drum discs 28 must extend.

'Ihe angle of the wedge 3 must be established. 1 prefer that it be 120; but this angle is not essential so long as the relationships are substantially as follows: Assuming 120, the maximum displacing effect that any one wedge can have on its cam without removing any of the other cams out of the range of influence of their wedges is 60. The total angular displacement transmittable to shaft I5 is therefore 60. 'I'he ratio of gear 22 to gear 23 must be the same as the total angular displacement of the tuning condenser shaft 24 bears to the displacement of shaft I5. If the standard form of condensers now obtainable, which have a total displacement of 180, is used, the ratio must be 180 to 60 or 3 to 1.

The apparatus is adjusted and works in the following manner: The cams I8 are loosened on shaft I5. A station is selected and tuned in by manipulating drum discs 28. A button which is to correspond to that station is selected and depressed to bring a cam into juxtaposition with it; a screw driver is inserted thru hole 2| and the position of the cam with respect to the shaft is fixed by tightening up on the set screw I8. This operation is repeated for all the buttons on the plate 8. Subsequently to get any so pre-determined stations it is only necessary to depress its button until its cam comes into registry with it. The button is then allowed to spring back into its inoperative position out of the way of future manipulations. As illustrated in Fig. 2, it is desirable that the tip of the wedge 3 protrude within the circle that would be described by the tips of the wings I9 and 20. This prevents the cam I8 from ever turning out of operative relation with respect to wedge 3.

The degree of accuracy by which the radio apparatus can be tuned in by this method and mechanism depends solely on two things: the amount of tolerance permitted in the tting between wedge 3 and the sides of the wings I9 and 20 of the cam, and the amount of free play or back-lash permitted between the gears 22 and 23. 'I'he tolerance in the former should be zero if the wedge and cam are properly designed to t each other; back-lash is no problem in the radio art and is easily overcome by any one of the usual means available such as splitting one of the gears, or placing one of them under the influence of a spiral spring (both are not shown here).

It is often desirable that the particular station to which the apparatus is attuned be set off in some manner other than on dial 2'I. To this end is supplied the device shown in Fig` 6: 32 is an electric light bulb whose base 22 is inserted into and held by the metallic ring 34. The ring itself is held within the insulating cup 35. From ring 34 extending thru the base 38 of the cup is the metallic strip 31 to which the electric lead wire 38 from the current source is soldered. 'I'he metallic spring finger 48 extends outwardly from the base 38 and is attached thereto by rivet 39. Rivet 39 is in contact with the base 33 of the light bulb. 'I'he other end of the current source (both not shown) is grounded to the shaft |5.

After the cams I8 have been adjusted and set, the cups 35 with bulbs 32 are inserted into tubes 2| of plate 8 from behind. In this position nger 40 (see Fig. 4) is just long enough to reach set screws I8 (or ItA to be described later) when the particular cam has been registered with its wedge. In this manner the lamp circuit is completed and the lamp is lit up. To cover the lamp, on the face of panel 3| in front of holes 2| are inserted annular rings 4| containing lenses 42 on which the station designation may be printed or otherwise inscribed.

A variation of the cams I8 and cam shaft I5 is shown in Figures 4 and 5. 43 is a shutter movable up and down between guide posts 44 extending upwardly from base 45. Friction between the shutter and the guide posts is reduced by rollers 48 supported by pins 41 between the forked ends 48 of the said shutter. The base plate 45 is fastened to a support by means of screws 49. Positioned in front of shutter 43 is -plate 8 carrying the buttons 2 and the lights 32 exactly as previously described. In shutter 43 directly opposite each button blade I is slot 50 substantially twice as long as the blade is wide; opposite each tube 2| is slot 5| somewhat larger than blade I is wide. Integral with shutter 43 between each pair of slots 50 and 5I are shelves 52,

Slidably positioned between shelves 52 are, what I choose to call, cam plates 53. 'I'hese are maintained in place partially by lips 54 of shelves 52 and partially by set screws I8 which pass thru the said plates and thru the smaller shutter slots 5| and screw into lock nuts 55 behind. Plates 53 contain slots 58 coinciding with slots 50 of the shutter and of a length slightly less than the width of blade I.

Centrally placed in the shutter 43 is the large slot 51 into one side of which is cut the teeth of the rack 58. Within this slot meshing with the rack 58 is gear 59 which is fixed to the condenser shaft 24. In Fig. 5 gear 59 is represented diagrammatically by its pitch and addendum circles. If the total angular displacement of shaft 24 is 180, the pitch diameter of gear 59 must be such that one half its perimeter, measured along the pitch circle, must be equal to one half the length of the slots 58 in plate cams 53.

Integral with shutter 43 and depending therefrom directly in line with rack 58 thru base plate 45 is rack 80. Meshing with rack 80 is gear 8| (shown by its pitch and addendum circles), and on the same shaft (not shown) with the latter gear is the Vernier turning knob represented by the clashed circle 82.

'I'he mechanism shown in Fig. 4 and Fig. 5'

is operated in a manner similar to the one shown in Figs. 1 and 2: A station is tuned in by operating the vernier 62.` A button head is depressed and the corresponding cam plate is brought to coincide with wedge 3 and positively fixed to the shutter 43 by tightening up on set screw I8'. The operation is of course repeated for all the buttons. Thereafter the stations are tuned in by depressing the button. The wedge forces the cam into alignment with itself and thereby raises or lowers the shutter, as the case might be, and simultaneously rotates the condenser shaft 24. It is important to note that when the wedge 3 and a plate 53 or a cam I8 coincide there set screws I8' or I8 are directly in back of holes 2|. The principal difference in the operation of cams I8 and 53 is that the angle of wedge 3 must be more acute for the plate cam.

Altho I have described the shutter type in Fig. 4 and Fig. 5 as being displaceable vertically, in reality as it is shown in the drawing it is designed to operate with horizontal displacement; the buttons t0 be in line vertically. For vertical disenvases placement of the shutter it would have to be counterbalanced against the action of gravity. The dashed lines 63 in Fig. 4 indicate the limits of shutter displacement.

I do not wish to be limited to wedge shaped followers; cams with followers of different shapes can be designed to do the work herein indicated to be done. Y

It should be noted that there are no dead spots in the mechanisms; that is, the wedges will operate their respective cams no matter in what position they are. The wedges are inclined from both directions so that they will activate their cams from either side of centerline. In other Words, no auxiliary mechanism is here required to return the wing cams or the shutter to a predetermined starting point before a succeeding button can be brought into play.

The operation of my push-button controls will be readily understood from the foregoing description; it can be seen that I have provided simple, inexpensive and efficient means for carrying out the objects of the invention. Furthermore, while I have particularly described the elements best adapted to perform the functions set forth, it is obvious that various changes in form, proportion and in minor details of construction may be resorted to Without departing from the spirit 'or sacrificing any of the principles of the invention.

What I claim is:

1. In combination for the tuning `of a radio apparatus or the like to a predetermined station: a cam follower containing a recess to coincide with the edges of a wedge shaped cam, means operatively linking the cam follower to the tuning element of the radio apparatus, and a yieldably mounted wedge shaped cam displaceable in a straight linear direction; the tuning ofy the apparatus being accomplished by depressing the cam against the cam follower to displace the same until the edges of the wedge and the above mentioned recess coincide.

2. In combination for the tuning of a radio apparatus or the like to a predetermined station: a substantially wedge shaped yieldably mounted cam follower displaceable in a straight linear direction to activate a cam follower, a cam follower operable by said cam from two directions containing a central depression substantially coinciding to the contour of the wedge, a shaft on which the cam follower is fixed, and means operably linking the shaft to the tuning element of the radio apparatus; the tuning of the apparatus being accomplished by depressing the cam against the cam follower to displace the same until the cam and the above mentioned depression in the cam follower coincide.

3. In combination for the tuning of a radio 'apparatus or the like to a predetermined station:

a yieldable Wedge shaped cam, a plate with a slot whose length is substantially equal to the width of said wedge and is positioned in proximity thereto, the said plate being displaceable in the directions parallel to said slot, and means operably linking the plate to the tuning element of the radio apparatus; the tuning of the apparatus being accomplished by depressing the wedge into the slot of the plate and displacing the same until the slot and wedge coincide.

4. In combination for the tuning of a radio apparatus or the like to a predetermined station: a yieldable wedge shaped cam, a plate with a slot therein whose length is substantially equal to the width of the active portion of said wedge and is positioned in proximity thereto, a carrier to a 3 which the plate is xed, means to adjust the position oi' the plate on the carrier, and means operably linking the carrier to the tuning element of the radio apparatus; the tuning of the apparatus being accomplished by depressing the cam into the slot of the plate and displacing the same until the slot'and wedge coincide..

5. In combination for the tuning ofa radio apparatus or the like to a predetermined station: a yieldable wedge shaped cam, a plate with a slot therein whose length is substantially equal to the width of the active portion of said wedge and is positioned in proximity thereto, a carrier to which the plate is fixed, means operably linklng the carrier to the tuning element of the radio apparatus, the tuning of the apparatus being accomplished by depressing the cam into the slot of the plate and displacing the same until the edges of the wedge and slot coincide, and means to indicate when the wedge and slot are in coincidence.

6. In combination for the control of a radio apparatus or the like, a wing-shaped cam follower, a yieldably mounted cam displaceable in a straight linear direction against the cam follower to displace the same to the position where the wings of said follower are symmetrically positioned relative to said cam, and means operably linking the cam follower to the apparatus to be controlled.

7. In combination for the control of a radio apparatus or the like, a wedge-shaped cam yieldably mounted and displaceable in a straight shaped cam to the position where both surfaces of the wedge are each in contact with a contact surface ofthe cam follower, and means operably linking the cam follower to the apparatus to be controlled.

8. In a device of the class described, means for yieldably mounting the actuating member comprising: the actuating member, a housing in which said actuating member is slidably supported, said actuating member being formed with a lateral aperture, spring means positioned within said aperture, and an abutment for the spring means fixed at the rear of the housing and passing through said aperture near one end thereof, the said spring means being compressible between said abutment and the opposite end of said aperture within said housing.

9. In combination for the control of a radio apparatus or the like, a wing-shaped cam follower, the wings of said cam being substantially 120 apart, the maximum possible operable displacement of said cam follower being substantially one-half the angle between said wings, a cam displaceable against said cam follower to displace the same to a central position with respect to said cam, and means operably linking the cam follower to the apparatus to be controlled.

10. A device for the control of a radio apparatus or the like comprising in combination a wing-shaped cam follower, a yieldably mounted cam movable against said cam follower to displace the same to a predetermined position, the tip of said cam when in inoperative position being disposed within the circle that would be described the device to be controlled.

l :si ,l

linking the cam with 

